documentq
DESCRIPTION
qTRANSCRIPT
-
5/19/2018 Q
1/28
OPTIMHOStatic Distance Protection Relays
-
5/19/2018 Q
2/282
OPTIMHOStatic Distance Protection Relays
Features
Full scheme distance relays with18, 12, 9 or 6 measuring units.
Phase and ground distance orphase distance protection.
Single or multiple zones.
Optional directional earth faultprotection.
Typical operating time: one cyclefor three phase faults.
Optional fault location includesmutual compensation on selectedmodels.
Optional data recording for postfault analysis and instrumentationfunctions.
Eight independent groups ofsettings can be stored in the
relay.
A second blocking scheme isavailable on selected models foruse with signalling equipment.
Integral user interface for easyaccess to relay setting and faultrecords.
Provision for remotecommunications via modems.
Benefits
Wide model range for accuratematching to applications.
Remote interrogation reducesneed for site visits.
Precise fault location, even ondouble-circuit lines together withfault information reduces outagetime.
Accurate fault informationprovides for in-depth faultanalysis.
Changes to alternative groups ofsettings can be accomplishedwith a single command.
Self diagnosis reducesmaintenance costs.
Vertical case option eases retrofitproblems.
Will interface with existingscheme logic.
Fulfils basic SCADA role at noextra cost.
Figure 1: Optimho (Type LFZP) relays
-
5/19/2018 Q
3/283
Summary Chart
Transmission and Sub-transmission Backsub transmission and distribution upmain protection main protection only
LFZP Model 111 112 113 114 121 122 123 131 132 151
Phase distance
Ground distance
DEF Fault location
Fault location with mutual compensation
Overhead lines
Underground cables
Open delta/3 limb VTs
No. of distance elements 18 18 18 12 12 12 12 9 6 6
Independent zones Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1 Z1
Z2 Z2 Z2 Z2 Z2 Z2
Z3 Z3 Z3 Z3 Z3 Z3 Z3 Z3
Reach stepped zones Z1X Z1X Z1X Z1X Z1X Z1X Z1X Z1X Z1X
Z1Y Z1Y Z1Y Z1Y Z1Y Z1Y Z1Y Z1Y Z1Y
Z2 Z2 Z2
Reversible zones
Single pole tripping
VT supervision
3 phase fuse blow supervision
Power swing blocking
Loss of load trip feature
No. of output contacts 24 24 24 24 16 16 16 16 16 8
Basic
Z1 Extension
Acceleration
PUR
PUR Unblock
Schemes POR1
POR1 Unblock
POR2
POR2 WI Trip
POR2 Unblock POR2 WI Trip Unblock
Blocking
Blocking 2
Z1, Z1X, Z1Y, Z2 Phase m m m m m m c f f
Distance Z1, Z1X, Z1Y, Z2 Ground q/m m m m q/m m c
Characteristic Z3 Phase L L L N N N P N
Z3 Ground Q/L L L D/N N N N
Negative sequence volts
DEF Zero seq current
polarising Zero seq volts Zero seq volts+current
= standard, = optional, m = shaped mho, f = fully crossed polarised mho, q = quadrilateral,c = shaped mho for cables, D = offset quadrilateral, N = offset lenticular, Q = D/rev q, L = N/rev m, P = N/rev f.For further information see Page 6.
-
5/19/2018 Q
4/284
Applications of Optimho
Optimho is produced in severalmodels, each suitable for a specificrange of applications. The moresophisticated models have featuresand functional abilities which canfulfil the most exacting duties.These can include ehv applicationsdepending on the fault clearancetime required. The more basicmodels have reduced hardware andsoftware to suit the simplerrequirements of sub-transmissionand distribution systems.
Optimho complements the wellestablished Micromho andQuadramho, enhancing the alreadyoutstanding family of distanceprotection available from ALSTOM
T&D Protection & Control Ltd.
The range of applications includes:
main and back-up protection ofoverhead lines and undergroundcables including transformerfeeders.
back-up protection oftransformers, auto-transformersand shunt reactors (LFZP 151)
protection of solid or resistance
earthed systems. Three-pole or single-and-three-
pole tripping, with or without theaid of a signalling channel.
single zone relays used inmultiple zone schemes to provideultra-high reliability by additionalredundancy of protection(LFZP 121, 122 or 132 with onezone enabled).
on-site replacement ofobsolescent electro-mechanical orswitched static distance relays.
protection of systems with open-delta line voltage transformers or3 phase 3 limb line voltagetransformers (LFZP 131 or 132).
phase selection to allow, forexample, a power line carrierphase comparison scheme (suchas P10) to carry out single phase
tripping (LFZP 114).
Principles of Operation
All models of Optimho are fullscheme distance relays which havea full set of measuring elements foreach main zone of protection.Compared with the switched type ofscheme, the full scheme systemimproves reliability by avoiding theneed to rely on phase selectionhardware or software and byremoving dependence on a singlemeasuring unit. Full scheme distancerelays are better able to cope withinter-circuit faults on double circuitlines and evolving faults.
The measuring element uses a micro-controller to produce a directsoftware equivalent of the hardwarephase comparator used in
Optimhos forerunners, Micromhoand Quadramho. This phasecomparator design is well tried,having accumulated nearly tenthousand relay years of successfuloperating experience over the lastdecade at locations throughout theworld.
Many of the other hardware andsoftware features of Quadramhohave been retained and further
enhanced in Optimho, ensuring thehighest standards of reliability.
Optimised Performancewith Distorted Signals
The phase comparators and leveldetectors use logic processing toachieve immunity from maloperationdue to noise, such as harmonicdistortion, travelling wave effects,high and low frequency capacitor
voltage transformer transients andcurrent transformer saturation.Operation of the phase comparatorsand level detectors can only occur ifthe input signals are dominated bypower frequency components.Filters are used to insure thisdominance and to optimiseoperating times.
Hardware Structure
All models are built up from a smallrange of standard printed circuitboards used as modular buildingblocks.
All models use the same relay case,power supply unit, and front panel.
The relay hardware is bus-structuredto allow printed circuit boards to beplugged into the case in differentcombinations. (See Figure 2).
The hardware uses multiplemicrocontrollers to perform ascomparators, level detectors, etc.A main microcontroller uses thedigital bus to read outputs from thesubsidiary microcontrollers, readsignals from the outside world via
optically coupled isolators,communicate with the user interfaceand perform scheme logic, serialcommunications, monitoring andoutput contact functions. Settings,indications, and fault records arestored in a type of memory which isunaffected by loss of dc supply.The layout of the relay case followsthe quiet region arrangementintroduced in Micromho andQuadramho, with measurement and
control boards located in ascreened compartment and fed withsignals from the outside world viascreened isolation devices andfilters. See Figure 3.
A vertical aspect, panel mountedversion can be used for replacingobsolescent electromechanicaldistance relays in narrow panels,with the minimum of paneldisturbance.
Integral User Interface
All relay settings and records areaccessible from the integral userinterface shown in Figure 4.
The liquid crystal display (LCD)indicates how the relay initiated thelatest trip. The faulty phase andzone are indicated for trips initiatedby the distance elements. The latestalarm condition is also indicated.
If indications are present when thesupply is lost, they are automaticallyreinstated when the supply isrestored.
-
5/19/2018 Q
5/285
The date and time of the fault,location (if available), and more,are displayed by pressing READ.After the indications have beenread, they can be cleared bypressing RESET, and the READ keycan then be used to step through allthe relay settings displayed insequence.
The cursor and SET keys, and the
two test sockets, are only accessibleafter removing the transparent frontcover. The keys are used to selectfrom a menu of options displayedon the LCD in English, and to enternew settings into temporarymemory. The menu has a simplestructure, allowing rapidfamiliarisation.
The SET key is used to transfertemporary entries to the permanent
memory which determines relayaction. Accidental changes areprevented by allowing SET to beoperative only at certain points inthe menu after appropriatewarnings have been displayed.
Figure 3: Mechanical layout of LFZP
Figure 4: User interface on front panel
User interface
8 Output relays
Statusinputs
8 Output relays
8 Output relays
Trips.alarms,etc.
Analoguebus
Main controller board+ Schemes, settings,
comms, monitoring diagnostics
Fault location board+ Fault data and instrumentation
Level detector board+ AC supply supervision
Zone 1 and 2 board(Alternatively zones 1, 2 and3)
+ Additional reach stepped zones
Zone 3 board+ Power swing blocking
DEF board
Quadrilateral
ground fault board
Settings fromdigital bus
Optional boards shown inbroken outline
AC inputs
Analogueinput
module
RS232C serial link to remote terminal
Digitalbus
VAVBVC
ABC
N
p
VN
7 Optical isolators
Output auxiliaryrelays andstatus input
optical isolators
Fully screenedpower supplyunit enclosureTerminal blocks
Terminal block Analogueinput module
Measurementand control
boards in fullyscreened
compartment
User interfaceon hinged front
panel
DISTANCEPROTECTION
SET
RESET ACCEPT/READ
RELAY AVAILABLE
PARALLEL
SERIAL
TRIP
ALARM
2 x 16 characterliquid crystal display Light emitting diodes
Test sockets7 Keys only RESET and ACCEPT/READaccessible with front cover in place
Figure 2: Electrical structure of LFZP
-
5/19/2018 Q
6/286
Menu Options
The menu holds an extensive rangeof options, including:
viewing records of the LCDindications from the last fourfaults.
printing records or settings on aportable printer plugged into theparallel test socket
entering a relay identificationcode for use on printouts.
comprehensive test options suchas: monitoring test points on theparallel socket; blocking outputcontacts (the relay inoperativealarm contact closes when theoutput contacts are blocked);simplified on-load directionaltesting; and closing selectedoutput contacts (for instance tocarry out a circuit breaker test)
setting up the baud rate andprotocol for the serialcommunications.
Settings
The setting options allow the user toselect functions to suit each
application. The available optionsdepend upon the model ofOptimho, but usually include:
scheme type
which distance zones areenabled (up to 5 zones)
whether ground fault timedelayed zones (if fitted) areenabled
direction of reach-stepped zones
or of Zone 3 (if fitted) whether start indications are
required for remote faults whichdo not result in a trip.
eight independent groups ofsettings which are stored in therelay memory and are selectablefrom the menu.
The menu is adaptive; for example,if Zone 2 is not required and hasbeen disabled, its time setting is
automatically removed from themenu.
Schemes Available
The scheme selection varies with themodel of Optimho. Most modelshave basic distance with up to 3independent zones available,designated Z1, Z2 and Z3.Additional zones 1X and 1Y areobtained, if required, by steppingthe reach of the Zone 1 elementsafter time delays started by theZone 2 and/or Zone 3 elements.On some models Zone 2 is obtainedby stepping the reach of Zone 1,while on some other models, Zone 3is omitted.
Models offering selectable,permissive overreach andunblocking schemes are completewith current reversal guard logic
and open breaker echo logic.
Models having independent Zone 1,Zone 2 and Zone 3 have additionalpermissive overreach andunblocking schemes with weakinfeed logic, also the blockingscheme. These schemes requireZone 3 to be set reverse looking.
Single phase tripping logic isavailable in some models.
Loss of load accelerated trippingfeature is available on some modelsfor use with 3 pole tripping.
-
5/19/2018 Q
7/287
Distance Characteristics
The phase comparator is arranged to produce several types of distancecharacteristics for the different models of Optimho. For further information seeSummary, Page 3.
Characteristic Descriptiontype
m Partially cross polarised shaped mho with partialsynchronous polarising for 3-phase faults. Expansionunder fault conditions is more than adequate to cover arcand tower footing resistance for most systems, withexcellent phase selection. See Figure 5.
f Fully cross polarised (or quadrature polarised) mho withpartial synchronous polarising for 3-phase faults.Similar to type m above but used where only phase faultprotection is required.
c Self polarised mho, with a small proportion of crosspolarising: used for ground fault protection of
underground cables at high and medium voltages.q Quadrilateral with adaptive reactance measurement to
avoid overreach or underreach for resistive faults withprefault load. The directional measurement is partiallycross polarised. The resistive reach setting is variable upto 150(1A relay) or 30(5A relay). The quadrilateralis used instead of type m above to cover ground faultresistance on overhead lines shorter than 15km, onresistance neutral systems, or on systems with high groundresistivity. See Figure 6.
D Offset quadrilateral: as type q but with reverse reach for
busbar back-up protection in Zone 3 time.N Offset lenticular with a variable aspect ratio set to avoid
load encroachment on long lines. A circular offset settingfor shorter lines is included. The reverse reach is used forbus back-up protection in Zone 3 time. Reach steppedzones whose timers are started by Zone 3 automaticallyavoid load encroachment if Zone 3 is shaped to avoid theload impedance. See Figure 7.
Q Selectable between type D and reverse type q.
L Selectable between type N and reverse type m.
P Selectable between type N and reverse type f.
Figure 5: Resistive expansion of partially cross-polarized mho under f ault conditions for solidly grounded systems
X
Numbers are source impedance/relay setting ratios
24 60
12610
R
-
5/19/2018 Q
8/288
Remote Communications
All the options available on themenu are also available from alocal or remote terminal via anRS232C serial communication port.Sockets are provided on both thefront and the rear of the relay fortemporary or permanent connectionrespectively. The socket on the rearcan also interface with a modem forcommunication over a suitable link,for instance a telephone line.
The facility to bulk transfer settings,event records and meteringinformation (providing a faultlocator is fitted) is available usingALSTOM T&D Protection & ControlLtd pc based software Opticom.
By using KITZ 103 interface unit, theOptimho can be interconnected torelays in the ALSTOM K range.The interconnection is via ashielded, twisted wire pair knownas K-Bus. Up to 32 relays may beconnected in parallel across the bus.The K-Bus is connected through asecond KITZ protocol convertoreither directly or via a modem to theRS232 port of the pc. The K-Bus isRS485 based and runs at
64 kbits/s.From the same pc, Opticom 100(version 5.0 and higher) and anyCourier based Access Softwarepackages can be used tocommunicate with the Optimho.
The KITZ 103 and the LFZP act as asingle slave device over K-Bus, seeFigure 8.
For more detailed information on theapplication of Optimho over K-Bus,
including modem connections, baudrates, bit framing and the use ofCourier features, reference shouldbe made to the following servicemanuals:
KITZ 101/102Interface Unit R8521
KITZ 103K-Bus to Optimho Interface R8532
OptiCom 100/140
Settings Databaseand File Transfer R5928
Figure 6: Quadr ilateral ground fault characteristics
Figure 7: Lenticular Zone 3
Zone3
Zone2
Zone1
Zone3reverse
Directionalline
Zones1&2
R
LHR
esis
tive
rea
ch
X
RH
Resis
tive
rea
ch
X
Zone 3
Zone 3reverse
a
b
0.410.67
1.00Aspect ratios a/b
Loadarea
R
-
5/19/2018 Q
9/289
Polarising
The partial cross polarising signalused in various distancecharacteristics is a square wavederived from a healthy phasereference and 16% of the amplitudeof the prefault voltage. This wave isadded to the faulty phase voltage,and dominates it for close-upunbalanced fault conditions.This provides a clear directionalreference even in the presence ofcapacitor voltage transformertransients.
The partial synchronous polarising is
similar to partial cross polarising butis effective for 3-phase faults.Synchronous polarising is derivedfrom prefault voltage and isavailable for 16 cycles after faultincidence to cover breaker failureprotection time.
Several cycles must elapse fromsystem energisation beforesynchronous polarising is available,so switch-on-to-fault logic is
arranged to provide protection forclose-up 3-phase faults during thisinitial period.
Directional Earth FaultProtection(not available in all models)
The directional earth fault protection(DEF) has these features selectablevia the user interface:
time delayed tripping, eitherdefinite time or inverse definiteminimum time using a selection ofbuilt-in IEC or American curves.See Figure 9.
instantaneous high-set tripping,available if the model of Optimhohas no Zone 1 instantaneous
ground fault elements fitted. aided tripping via permissive
overreach, unblocking, orblocking schemes (depending onthe model), which work inconjunction with the distancescheme, sharing the samesignalling channel.
choice of polarising for thedirectional element:
negative sequence voltage
derived from internal filters(compared against negativesequence current).
zero sequence current from aseparate current input
zero sequence voltage (in somemodels) derived internally fromVA, VBand VC.
dual zero sequence current and
voltage (some models only).
The overcurrent elements use zerosequence current as the operatingquantity irrespective of the type ofpolarising used for the directionalelement.
The negative sequence filters areself-adaptive to system frequency,allowing greater sensitivity than ispossible with fixed filters tuned tothe nominal system frequency.
A magnetising inrush currentdetector is provided to preventmaloperation when energising in-zone transformers. The circuit usesthe principle of detectingzeros in the current lasting for aquarter-cycle or more. This methodis inherently unaffected by currenttransformer saturation, unlikesecond harmonic restraint.
Figure 8: Typical application diagram: KBUS/LFZP 100 (Optimho) Interface Type KITZ 103
Auxiliarysupplyvoltage
KITZ101/102KBUS/IEC 60870 Interface+
_
Screen
Screen
All points are internally connected
2 TX3 RX 7 Signal GND 1 Protective GND
IBM or compatible P.C.(For pin assignmentnumbers see table)
Auxiliarysupplyvoltage
12
150R
KITZ103 KBUSLFZP 100 (Optimho)
Interface
LFZP 100 (Optimho) Relay +_
All points are internally connected
2371
2 TX3 RX
7 Signal GND 1 Protective GND
12
*
54
56
150R
Typical Kseries relay
When Fitted
Terminals
Screen Link
56
54
Typical Kseries relay
Terminals
(Rear Port)
Table showing connections between KITZ 103 serialport and LFZP 100 (OPTIMHO) rear serial port.(For reference only. Please refer to PC user manualwhere available).
KITZ 103 LFZP 100 (OPTIMHO) rear serial port type
25 pin D male connector (DTE) KITZ 103 25 pin D male connector (DTE)
1 Protective ground 1 Protective ground
2 Transmitted data 2 Received data
3 Received data 2 Transmitted data7 Signal ground 7 Signal ground
Connector shell to cab le screen Connector shell to cable screen
-
5/19/2018 Q
10/2810
Fault Location, FaultData Recording andInstrumentation(not available in all models)
The fault location algorithm includescompensation for infeed into aresistive fault from remote source
with prefault load flow. Readout ofthe fault location can be selected tobe in kilometres, miles or percent ofline length.
Some versions of the fault locatorcan be mutually compensated ifrequired. This feature can not beused if zero sequence currentpolarising is required for the DEF.
The fault location board alsocomputes prefault and fault voltagesand currents phase-by-phase.These values, together with negativeand zero sequence current andvoltage can be read out to allowanalysis of the power systemnetwork as it was at the time of
fault. The duration of the fault is alsodetermined.
At any time under healthy live lineconditions, the line voltages,currents, watts and vars can becalculated on demand. These valuescan be compared with otherinstrumentation for accuracy.
As the fault location hardware islargely separate from that of thedistance measuring elements,protection accuracy can be cross-checked with fault location accuracyduring secondary injection tests.
All voltages and currents are givenwith phase angle relative to prefault
VA, and rms amplitudes in primaryor secondary terms.
Figure 9: DEF Protection time delay trip times
10
1
0.1
OperatingTimet(second
s)
1 5 100
OperatingTimet(second
s)
Current (Multipule of s)American curves
Current (Multipule of s)IEC curves
100
Curve 5 US moderate inverse
Curve 6 US standard inverse
Curve 7 US very inverse
Curve 8 US extremely inverse
Curve 1 S tandard inverse: t = 0.140.021
Curve 2 Very inverse: t = 13.51
Curve 3 Ex treme ly inverse: t = 8021
Curve 4 Longtime earth fault: t = 120
1
5
0.5
10 50
50
1 5 10010 50
Curve 5
Curve 6
Curve 7
Curve 8
Curve 4
Curve 1
Curve 2
Curve 3
10
0.1
100
5
0.5
50
1
-
5/19/2018 Q
11/2811
Figure 10: 50Hz operating times (MHO characteristic)
Figure 11: 60Hz operating times (MHO characteristic)
Figure 12: 50Hz operating times (quadrilateral characteristic)
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)
20 40 60 800 100
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)
20 40 60 800 100
Source impedenceRelay setting = 1
Minimum
MeanMaximum
Mean
Minimum
MaximumSource impedence
Relay setting = 30
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)
20 40 60 800 100
Maximum
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)20 40 60 800 100
Source impedenceRelay setting
= 30Source impedence
Relay setting= 1
Maximum
Mean Mean
Minimum
Minimum
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)
20 40 60 800 100
Maximum
Mean
MinimumMinimum
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)20 40 60 800 100
Source impedenceRelay setting
= 30 Source impedenceRelay setting
= 1
Maximum
Mean
-
5/19/2018 Q
12/2812
Self-Monitoring andVoltage TransformerFuse/MCB Supervision
Optimho has comprehensivecontinuous self-monitoring. If afailure occurs, an alarm is issued byclosing the relay inoperative alarmcontact and extinguishing the relayavailable LED. Diagnosticinformation is automatically
displayed if the failure is such that itdoes not disable the main processorand LCD.
Monitoring of the analogue circuitsincludes (i) the dc supply and allinternal dc power supply rails, and(ii) the ac supplies and internalanalogue voltage and currentcircuits (the latter only if the modelof Optimho has voltage transformersupervision).
The VT supervision logic can be setto block relay operation in the eventof failure of a VT fuse. The VTsupervision logic can be selectedvia the menu to self reset, or toremain sealed in until the resetbutton is pressed. All models havean optically coupled isolator tomonitor the auxiliary contact of aminiature circuit breaker if the VTsupplies are protected by an MCBinstead of fuses. Energising the
optical isolator blocks relayoperation.
Figure 13: 60Hz operating times (quadrilateral characteristic)
In addition, an optional externaldevice for monitoring 3 phase fuseblow via the RELAY BLOCKED opto-isolator is available.
Monitoring of the digital circuitsincludes (i) bus communications(ii) checking of RAM and EEPROMand (iii) watchdog circuits for everymicrocontroller. In the event offailure, trip signals originating fromthe affected part of the relay are
blocked.In models with quadrilateral groundfault characteristics, remedial actionis performed if the quadrilateralmeasuring circuits fail.The alternative shaped mho groundfault measuring elements, located ona different board, are automaticallybrought into action to restore theground fault protection. On powersystems where most faults areground faults, this capabilityconsiderably increases the overallavailability of the relay.
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)
20 40 60 800 100
0.03
OperatingTime(s)
0.04
0.02
0.00
0.01
Fault location (% of relay setting)
20 40 60 800 100
Source impedenceRelay setting
= 30Source impedence
Relay setting= 1
Minimum
Maximum
Mean
Maximum
Mean
Minimum
-
5/19/2018 Q
13/2813
Contact Arrangements
Most models are pre-programed togive a choice of at least two outputcontact arrangements. One of theseis arranged to give direct access tothe relays measuring units via theoutput relay contacts, so that acustomers existing protectionscheme can be operated inconjunction with Optimho ifrequired. The other arrangementstake advantage of the Optimhosown integral scheme logic.
Other Options
To be specified with order.
A facility to control the setting groupselected via five optical isolators is
available on all models.A facility to control the setting groupselected via three optical isolators isavailable on all models. Full schemeoptions are provided and threesetting groups are available.
Selection Chart 1
START
Ground Fault Distance?
Yes No
No
Either of the following:*voltage transformer supervision?*power swing blocking?
Yes
Any of the following:*week infeed POR unblocking scheme?*blocking scheme?*back-up for reverse faults?
Yes No
LFZP 132With DEF
OK for open-deltaOr 3limb VTs
Optional fault locaton
LFZP 131With DEF
OK for open-deltaOr 3limb VTs
Optional fault locaton
Yes No
Quadrilateral groundfault elements?
No
Any of the following?*weak infeed POR/unblocking scheme?*blocking scheme?*backup for reverse faults?*power swing blocking?
Yes
LFZP 121Optional fault
location
Yes No
LFZP 112Optional DEF.
Optional fault locator
LFZP 114Optional DEF.
Optional fault locator
Any of the following:*single pole tripping?*permissive undereach scheme (PUR)?*permisssive overreach Scheme (POR)?
*unblocking scheme?*power swing blocking?
No
Quadrilateral groundfault elements?
LFZP 111Optional DEF.
Optional fault location
Yes No
Yes
In some models specified above, it will be necessary to disable unwanted zonesand facilities with settings on the menu.
LFZP 122Optional fault
location
DEF Scheme?Go tochart 2
Undergroundcables?
No
Yes
-
5/19/2018 Q
14/2814
Selection Chart 2
Selection Chart 3
In some models specified above, it will be necessary to disable unwanted zonesand facilities with settings on the menu.
START
Yes No
Go to chart 1
LFZP 113Optional fault location
Optional DEF
LFZP 123Optional fault location
No DEF
Yes No
Underground cables?
Any of the following?*single pole tr ipping? * blocking scheme?*PUR scheme? * power swing blocking?*POR scheme? * c apacitor voltage*unblocking scheme? transformers?
START
Any of the following:*single pole tripping?*power swing blocking?*DEF?
Either of the following:*offset characteristic?*power swing blocking?
LFZP 112Optional DEF.Optional fault
location
No
No
Yes
Yes No
Yes No
Offset characteristic
LFZP 151No faultlocation
LFZP 114Optional DEF.Optional fault
location
LFZP 122Optional fault
location
Either of the following:*offset characteristic?*power swing blocking?
YesLFZP 131
with DEF.Optional faultlocation
LFZP 132
with DEF.Optional faultlocation
Offset characteristic?
No
Any of the following:
*ground fault distance?*voltage transformer supervision?*power swing blocking?
Single Zone Distance?
Yes
Go to chart 1
In some models specified above, it will be necessary to disable unwanted zonesand facilities with settings on the menu.
-
5/19/2018 Q
15/2815
Figure 14: Case connection diagram for relay inputs
A
BCPhase rotation
Direction of power flow for operation
P2 P1
S2A
B
C
A B C
N
a b c
Fusesor MCB
DEF current polarisation when required
S2
P1P2
2A27 2A282A25 2A26
2B27 2B28
2B25 2B26
2B23 2B24
2B21 2B22
2A23 2A24
2A21 2A22
2A11 2A12
2A9 2A10
2A7 2A8
2A5 2A6
2A3 2A4
2A1 2A2
MMLGTest block orEquivalent
LFZP 11119
20
21
22
23
24
25
26
15
16
17
18
27
28
+
2B13 2B14 2A13 2A14
2B 9 2 B1 0
2B7 2B8
2B1 2B2
2B5 2B6
2B11 2B12
2B3 2B4
15 70
19 74
3 58
11 66
78
7 62
23 82
A13
CRX
COX
RZ1X
CB AUX
MCB
IPD
R1
17
1
9
13
5
21
External resistor boxrequired for 220/250V
supply only
2A17
2B17
2A 18
2B18
49
77
DC supply
Signal receive
Channel out of service
Rest zone 1 extension
Breaker open
Relay blocked
Inhibit PSB, DEF, WI.
Reset indications
Signal send51
2B20 2B 19
2A 20 2A 19
79
84
64
80
68
60
72
76
14 2A16 2A15 2B16 2B15
a
b
c
Fusesor MCB
Alternative voltagetransformer connectionfor LFZP 131 & 132
Test block LFZP
15
16
17
18
Any Trip
S1
Optoisolator inputs when required:
CRX Open contac t from signalling channe l
COX Close contact f rom s ignall ing channelRZIX Open contact f rom autoreclose relay
CBAUX Closed circuit breaker contacts connectedin series to indicate all poles open. Requiredwith busbar VT or if the weak infeed or echofeature of POR scheme are required
MCB Closed contact from minature circuit breakerrequired when no VT fuses are used
RI Open contact to reset visual indications
IPD Open contac t from autoreclose re layrequired with single phase tripping if PSBor DEF options are used. Opto must beenergised during single pole dead times
For the unblocking mode of operation use CRX forthe unblock frequency (trip frequency) and RZIX
for the block frequency (guard frequency)
-
5/19/2018 Q
16/2816
Technical Data
Ratings
AC voltage Vn: 100 to 120V rms phase-phase
AC current In: 1A or 5A rms per phase
Frequency fn: 50Hz or 60Hz
Operating frequency range: 47 to 51Hz or 56.4 to 61.2 HzDC Supply Vx(1): For switched mode dc/ac/dc power
supply unit, available in three versions:
Nominal Operative Maximumrange withstand
48/54V 37.5 to 60V 64.8V
110/125V 87.5 to 137.5V 150V
220/250V 175 to 275V 300V
There is negligible change of accuracy with change ofvoltage within the operative range of the relay.
DC supply Vx(2): For optically coupled isolators.Supply options are the same as Vx(1).External resistor box provided for 220/250V version(see Figure 16).
Maximum overload ratings
AC voltage: 1.2Vnfor measuring accuracy1.5Vncontinuous withstand2.5Vnwithstand for 10s.
AC current: 2.4Incontinuous withstand100Inwithstand for 1s (In= 1A)80Inwithstand for 1s (In= 5A)
Burdens
AC voltage circuits: 0.1 VA per phase at Vn
AC current circuits: 0.08 VA per phase (In= 1A)0.5 VA per phase (In= 5A)
DC supply (1): 18W under healthy live lineconditions at Vx(1) 28W maximum
DC supply (2): 10mA per energised opticallycoupled isolator at Vx(2).
Distance elements
Range of positive sequence settings referred to line VT and CT secondaries:
All employed zones except reverse Zone 3:
Overhead line models 0.2 to 250(In= 1A)0.04 to 50(In= 5A)
Underground cable models 0.1 to 125(In= 1A)0.02 to 25(In= 5A)
Reverse Zone 3
Overhead line models 0.04 to 250(In= 1A)
0.008 to 50(In= 5A)
Underground cable models 0.02 to 125(In= 1A)and LFZP 151 0.004 to 25(In= 5A)
-
5/19/2018 Q
17/2817
Reach setting method is by digitally controlled analogue attenuators.Attenuation factors KZPh and KZN operate on current signals and arecommon to all zones.
Attenuation factors KZ1, KZ1X, KZ1Y, KZ2, KZ3 and KZ3 operate onvoltage signals and are specific to Zone 1, Zone 1X, Zone 1Y, Zone 2,Zone 3 forward and Zone 3 reverse respectively. The positive sequencereach for Zone 1 is given by:
Zone 1 = KZ1. KZPh.5/Infor overhead line models.
Zone 1 = KZ1. KZPh. 5/2Infor underground cable models.
Either KZ1 or KZPh is set to 1.000. To obtain the formula for each of theother zones employed, replace KZ1 by the appropriate attenuation factor forthe zone.
Extra settings for ground fault distance:
Residual compensation factor:
KZN=
ZL0 ZL1KZPh 3ZL1
Where ZL0and ZL1are the phasor values of zero and positive sequence
impedance of the protected line.
Quadrilateral resistive reach settings:
Right hand reach = KR.5/In
Left-hand reach = KR.6/In(LFZP 111)
Left-hand reach = KR.5/In(LFZP 121)
Range of factors: KZPh 0.040 to 1.000 in steps of 0.001
KZN 0.000 to 1.360 in steps of 0.001
KZ1KZ1X
KZ1Y 1.00 to 49.98 steps of 0.02KZ2KZ3
KZ3 0.2 to 49.9 in steps of 0.1
KR 1 to 30 in steps of 1
Range of setting of Zone 3 lenticular aspect ratio:
a/b = 1.00, 0.67 or 0.41
Characteristic angle settings:
Ph = arg ZL1to nearest available setting.
Ph = 50to 85in 5steps (overhead line models)
Ph = 45to 80in 5steps (LFZP 113 only)
Ph = 20, 25, 30, 35, 40, 50, 60or 70 (LFZP 123 only)
Vectorial residual compensation for ground fault distance:
N = arg (ZL0 ZL1) to nearest available setting
N = 50to 85in 5steps (overhead line models)
N = 45, 35and 25to 80in 5steps (LFZP 113 and 123 only)
Note: LFZP 113 is not designed to be used with a ground fault loop setting(2ZL1+ ZL0) /3 with an argument less than 30.
-
5/19/2018 Q
18/2818
Minimum operating values of the distance measuring elements forall types of fault:
Voltage: zero
Current: 0.05In/KZPh.
Accuracy: Reach: 5% at 2Inand 20C
Dynamic range: up to 25Infor faultlocator and instrumentation up to
56Infor distance protectionCharacteristic angle: 2
Resetting ratio: 105%
Timer ranges: Zone 1X timerZone 1Y timer each timer 0.10s to 9.98sZone 2 timer in steps of 0.02sZone 3 timer
Scheme co-ordination timers used in permissiveoverreach, unblocking and blocking schemes:
TP
TD 0 to 98ms in steps of 2msTDW
Timer accuracy: 1% of setting and 3ms.
Operating time: Typical relay operating times for Zone 1 are shown inFigures 10 to 13.
Mho characteristic (type m, f or c) 50Hz minimum: 14mstypical: 18ms
60Hz minimum: 12mstypical: 16ms
Quadrilateral characteristic (type q) 50Hz minimum: 16ms
typical: 23ms
60Hz minimum: 15mstypical: 20ms
Reset time: The trip contacts are sealed in for 60ms following theinitial contact closure. Thereafter, the maximum resettime is 35ms.
Power swing blocking
Power swing detected by transit time of impedance between Zone 6 andeither Zone 2 or Zone 3 as selected. Zone 6 is offset mho or offset lenticular,with the same range of forward and reverse reach settings and aspect ratios
as Zone 3.
Zone 6 timer range: 20ms to 90ms in steps of 5ms
Power swing detection regimes:
(i) detection disabled.
(ii) detection indicated only.
(iii) indication plus blocking of any one or moreselected zones.
Blocking disabled if a ground fault or (if DEF fitted) a phase fault occursduring a power swing.
-
5/19/2018 Q
19/2819
Directional earth fault
Directional measuring elements: one forward-looking, one reverse-looking:
Current sensitivity determined by current level detector:0.05Into 0.80Inin steps of 0.05In
Sensitivity of polarising quantity is 1V residual voltage of1.5% polarising current, as appropriate, depending uponthe type of polarising selected.
Characteristic angle G = 10to 80in 10steps.Instantaneous trip (available only if no Zone 1 ground fault distanceelements fit):
Setting range: 0.2Into 30Inin steps of 0.05In
Accuracy: 5% at fn, 20C
Aided trippingscheme: Scheme co-ordination timers:
TPG 0 to 98ms in steps of 2msTDG
High set current level detector 0.05In
to 0.80Inin steps of 0.05InTime delay trip: Setting Is= 0.05Into 1.20Inin steps of 0.05In
Time curves: eight curves and three definite time rangesshown in Figure 9.
Time multiplier: *t = 0.025 to 1.000 in steps of 0.025
Accuracy at fn, 20C, *t = 1, Is= 0.05Into 0.80In:
Current: +10% 0%
Operating time: definite time 3% over 1.3Isto 31Is
curves 1, 2, 4, 5, 6, 7, 8 5% over 2Isto 31Is
curve 3 7.5% over 2Isto 20Is
Fault location and instrumentation
Fault location positive sequence settings referred to line VT and CTsecondaries:
Range: 0.2to 200(In= 1A)0.1to 100(In= 1A) (113/123)
0.04to 40(In= 5A)0.02to 20(In= 5A) (113/123)
Setting: Zone F = KZF. KZPh.5/Infor overhead line models.Zone F = KZF. KZPh.5/2Infor underground cable models.
KZPh and residual compensation are common to the distance measuringelements.
KZF range: 1.00 to 40.00 in steps of 0.01.
Line length setting (in miles or km or %)
0.00 to 99.99 in steps of 0.01
100.0 to 999.9 in steps of 0.1
KZM and M are provided for mutually compensating the fault locator ifrequired:
KZM range: 0.0 to 1.36 in steps of 0.001
M range: 50to 85in steps of 5
Accuracy 2% at 2In, fn, 20C.
Settings to allow for transformer ratios for instrumentation functions:
CT ratio: 1:1 or 10 to 5000: 1 in 10:1 steps
VT ratio: 1:1 or 10 to 9990: 1 in 10:1 steps
-
5/19/2018 Q
20/2820
Block or enable reclose logic
A normally-open or normally-closed contact is supplied on most models toblock or enable reclose respectively.
The menu allows the following choices of logic:
Reclose blocked or enabled on:
Zone 1 or aided trip caused by 2 or 3 phase fault
Zone 1 or aided trip cased by 3 phase faultZone 1X and/or Zone 1Y and/or Zone 2 timedelayed trip
Channel out of service
DEF instantaneous and/or aided trip and/or delayed trip.
Voltage transformer (fuse fail) supervision
The voltage transformer supervision (VTS) operates when zero sequencevoltage is detected without the presence of zero sequence current, by meansof the low set neutral level detector. The VTS does not limit the distance relaycurrent sensitivity or operating times for line faults even when the VTS is set toblock relay tripping.
Nominal Vo detector setting 9.5V
The blocking action of the VTS on distance comparators can be removed bymenu selection via the user interface.
Switch-on to fault logic
Menu choices allow instantaneous trip and alarm and indication for faultsoccurring on line energisation, whether bus or line voltage transformers areused:
SOTF enabled either 0.2s or 110s after line de-energised
(110s prevents SOTF action on auto-reclosure).SOTF trip via measuring elements.
SOTF trip via current and voltage level detectors.
Output contacts
Some of the available arrangements are shown in Table 1.
Ratings:
Make and carry 0.2s 7500VA subject to a maximaof 30A, 300V, ac or dc.
Carry continuously 5A ac or dc.
Break ac: 1250VAdc: 50W resistive
25W L/R = 0.04sSubject to a maxima of 5Aand 300V
Durability
Loaded contact 10,000 operations minimum
Unloaded contact 100,000 operations minimum
-
5/19/2018 Q
21/2821
High voltage withstand
Dielectric withstandIEC 60255-5:1977 2kV rms for 1 minute between allANSI C37.90:1978 terminals and case earth.
2kV rms for 1 minute betweenterminals of independent circuits,with terminals on each independentcircuit connected together.
1.5kV rms for 1 minute acrossnormally open contacts
High voltage impulseIEC 60255-5:1977 Three positive and three negative
impulses of 5kV peak, 1.2/50s,0.5J between all terminals and allterminals and case earth.
Insulation resistanceIEC 60255-5:1977 >100Mwhen measured at
500V dc
Electrical environment
DC supply interruptionIEC 60255-11:1979 10ms interruption in the auxiliary
supply under normal operatingconditions, without de-energising.
High frequency disturbanceIEC 60255-22-1:1988 Class III 2.5kV peak between independent
circuits and between independentcircuits and case earth.
1.0kV peak across terminals of the
same circuit.Electrostatic dischargeIEC 60255-22-2:1996 Class 3 8.0kV discharge in air with cover
in place
6.0kV contact discharge withcover removed.
Fast transient disturbanceIEC 60255-22-4:1992 Class IV 4.0kV, 2.5kHz applied directly to
auxiliary supply
4.0kV, 2.5kHz applied directly toall inputs
Radio frequency interferenceEMC compliances Compliance to the European89/336/EEC Commission Directive on EMC isEN50081-2:1994 claimed via the TechnicalEN50082-2:1995 Construction File route.
Generic Standards were used toestablish conformity.
-
5/19/2018 Q
22/2822
Atmospheric environment
TemperatureIEC 60255-6:1988 Storage and transit 25C to +70C
Operating 25C to +55C
IEC 60068-2-1:1990 Cold
IEC 60068-2-2:1974 Dry Heat
HumidityIEC 60068-2-3:1969 56 days at 93% RH and 40C
Enclosure protectionIEC 60529:1989 IP50 (dust protected)
Mechanical environment
VibrationIEC 60255-21-1:1988 Response Class 1
SeismicIEC 60255-21-3:1993 Class 1
-
5/19/2018 Q
23/2823
Table 1. Standard output contact case terminal connections
Terminal LFZP 111, 112, 113, 114(Note 1) LFZP 121, 122, 123 LFZP 131,132 LFZP 151
29-31 RIA 97Y RIA 97Y RIA 97Y RIA 97Y
29-33 VTS 97X VTS 97X Def Trip 67N VTS 97X
29-35 Dist Trip 21 Z Z1 Dist Trip 21 Trip 94T
37-39 Trip A 94A Trip 94T Trip 94T Trip 94T
41-43 Trip B 94B Trip 94T Trip 94T Trip 94T
45-47 Trip C 94C Trip 94T Trip 94T Trip 94T
49-51 Signal Send 85X Signal Send 85X Signal Send 85X Any Trip 94
53-55 SOTF 98 SOTF 98 SOTF 98 Start 99
30-32 Time delayed 21/67N(T) Z1X + Z1Y(T) Z1X/Z1Y(T) Z1X + Z1Y + Z2(T) Z1X/Z1Y/Z2(T) (Note 2)
30-34 DEF Trip 67N Z2(T) Z2(T) Z3(T) Z3(T) (Note 3)
30-36 Aided Trip 94Y Z3(T) Z3(T) Def(T) 67N(T)
38-40 Trip A 94A Aided Trip 94Y Aided Trip 94Y
42-44 Trip B 94B Trip 94T Any Trip 94
46-48 Trip C 94C Any Trip 94 Signal Stop 85Y (Note 4)
50-52 Bar 96 Bar 96 Bar 96
54-56 Start 99 Start 99 Start 99
57-59 Trip A 94A
57-61 Trip B 94B
57-63 Trip C 94C
65-67 Trip A 94A
69-71 Trip B 94B
73-75 Trip C 94C
77-79 Any Trip 94
81-83 PSB 95
Notes:
1. When 3 phase tripping scheme is used,94A, 94B, 94C and 94 all respond as 94T.
2. Z1X/Z1Y(T) in LFZP 132.
3. Z2(T) in LFZP 132.
4. Trip 94T in LFZP 132.
Key to contact functions.
97Y Relay inoperative alarm. 94Y Aided trip.
97X Voltage transformer supervision 94 Any trip
95 Power swing blocking. 94A Trip pole A of breaker.
21 Distance trip. 94B Trip pole B of breaker.
67N DEF trip. 94C Trip pole C of breaker.
98 Switch on to fault trip. 94T Trip all poles of breaker.
Z1 Zone 1 trip. 96 Block autoreclose.
Z1X(T) Zone 1X time delay trip. 85X Signal send.
Z1Y(T) Zone 1Y time delay trip. 85Y Signal stop.
Z2(T) Zone 2 time delay trip. 99 DEF element operated (forward or reverse)
21/67N(T) Any time delay trip.or any Zone 1, 2 or 3 element.
-
5/19/2018 Q
24/2824
Figure 15a: Arrangement and outline: Optimho panel mounting vertical
Figure 15b: Arrangement and outline: Optimho panel mounting horizontal
T.B.
T.B.
T.B.
25 way 'D' connector detail
14
13
25
1
Terminal block detail
2
27
28 28 way maxEach way accepting:-
2M4 Ring terminalsor24,8 x 0,8Snap-on terminalsor1 Ring+1 Snap-on terminal
1
414.00
177.00
Hingedpanel
Rear view
25 way 'D'connector
Power supplyM4 earth
connections
BoardRef1234567
89101112137oror
Description
Opto isolatorOutput relayOutput relayOutput relayAssy fault locator module3 Zone gnd fault quadSee below
Level detectorDirectional earth fault1 Zone offset lenticularProcessorAC input 2AC input 12 Zone mho ph & gnd1 Zone mho reversibleZone 3 ph (2 channel)
Board No.
ZJ0133ZJ0140 003ZJ0140 001ZJ0140 002GJ0277 000ZJ0132
ZJ0136ZJ0139ZJ0131ZJ0138ZJ0135ZJ0134ZJ0130ZJ0146ZJ0129
1234
Input/Output
Processing
ACinput
Front view
1213
2956
5784
411.00 362.60
24.20
159.00
168.00
Panel cut-out detail
4 Holes4,4
10.00
312.00
32.00
157.00
Bottom view
Front view
1110
9 7 58 6
Ribbon cable
25 way 'D' connector detail
14
13 25
1
Terminal block detail
2
27 28
28 way maxEach way accepting:-2M4 Ring terminalsor24,8 x 0,8Snap-on terminalsor1 Ring+1 Snap-on terminal
1
T.B. T. B. T. B.
414.00
177.00(4U)
Hinged panel
Front view
32.00 312.00
10.00
157.00
Side view
Rear view
25 way 'D'connector
Power supply
M4 earth connection
BoardRef123456789
101112
137oror
Description
Opto isolatorOutput relayOutput relayOutput relayAssy fault locator module3 Zone gnd fault quadSee belowLevel detectorDirectional earth fault1 Zone offset lenticularProcessorAC input 2
AC input 12 Zone mho ph & gnd1 Zone mho reversibleZone 3 ph (2 channel)
Board No.
ZJ0133ZJ0140 003ZJ0140 001ZJ0140 002GJ0277 000ZJ0132
ZJ0136ZJ0139ZJ0131ZJ0138ZJ0135
ZJ0134ZJ0130ZJ0146ZJ0129
1 2 3 4
Input/Output
Processing ACInput
Front view (panel removed)
5
67891011
1213
29
56
57
84
411.00362.6024.20
159.00 168.00
Panel cut-out detail
4 Holes 4,4
Ribboncable
-
5/19/2018 Q
25/2825
Figure 15c: Arrangement and outline: Optimho rack mounting
Figure 16: Outline - external component box
25 way 'D' connector detail
14
13 25
1
Terminal block detail
2
27 28
28 way maxEach way accepting:-2M4 Ring terminals
or24,8 x 0,8Snap-on terminalsor1 Ring+1 Snap-on terminal
1
T.B. T. B. T. B.
483.00
465.10
177.00(4U)
Hinged panel Front view
101.60
37.70
34.00 312.00
10.00
157.00
Side view
Fixing slot10,6 long x 7 wide
1 2 3 4
Input/Output
Processing ACinput
Front view (panel removed) Rear view
25 way 'D'connector
Power supplyM4 earth connection
BoardRef123456
789
101112137oror
Description
Opto isolatorOutput relayOutput relayOutput relayAssy fault locator module3 Zone gnd fault quad
See belowLevel detectorDirectional earth fault1 Zone offset lenticularProcessorAC input 2AC input 12 Zone mho ph & gnd1 Zone mho reversibleZone 3 ph (2 channel)
Board No.
ZJ0133ZJ0140 003ZJ0140 001ZJ0140 002GJ0277 000ZJ0132
ZJ0136ZJ0139ZJ0165ZJ0138ZJ0135ZJ0134ZJ0130ZJ0146ZJ0129
567891011
12
13
28 way maxEach way accepting:2 - M4 ring terminalsor2 - 4,8 x 0,8 Snap-on terminalsor1 - Ring + 1 - Snap-on terminal
M4 earth connection
155
2
27 28
Perforated cover
Channel used whenmounted in Midosscheme. (See note)
120M4 tapped panel fixing holesscrews not provided10
121
15
36.3
Terminal screws: M4 x 8 brass cheese head
with lockwashers are provided
Note: Where the box is to be fitted into aMidos scheme it should be positionedbetween relays, not at a tier end.Rack mounting schemes require theaddition of joining strips and spacers.
-
5/19/2018 Q
26/2826
Cases
The relay is housed in a multi-module Midos case suitable for rackor panel mounting, as shown inFigure 15.
Weight: 15kg.
Other InformationAn LFZP accessory kit is available tofacilitate commissioning and test.
-
5/19/2018 Q
27/2827
Information Requiredwith Order
LFZP model required (see SummaryChart page 3)
Whether DEF required (if optionalfor model selected)
Whether fault location required(if optional for model selected)
Nominal current rating In: 1A or 5A
Frequency fn: 50Hz or 60Hz
Voltage of dc supply Vx(1):48/54V, 110/125V or 220/250V
Voltage of dc supply Vx(2):48/54V, 110/125V or 220/250V
Mounting arrangements: rack, panelhorizontal, panel vertical, semi
projection
Whether the block auto-reclosecontact 961 is to be a normally-open or normally-closed contact
Whether the signal send contact85X-1 is to be a normally-open ornormally-closed contact
Advice is available when theinformation requested above isdifficult to specify
Requests for advice should include: current and voltage transformer
ratios
positive and zero sequenceimpedances of the protectedfeeder or full details of the feederlengths and construction
source impedances or fault levelsfor both minimum and maximumplant conditions
-
5/19/2018 Q
28/28
St Leonards Works, Stafford, ST17 4LX England
Tel: 44 (0) 1785 223251 Fax: 44 (0) 1785 212232 Email: [email protected] Internet: www.alstom.com
1999 ALSTOM T&D Protection & Control Ltd
Our policy is one of continuous development. Accordingly the design of our products may change at any time. Whilst every effort is made to produce up to date literature, this brochure shouldonly be regarded as a guide and is intended for information purposes only. Its contents do not constitute an offer for sale or advice on the application of any product referred to in it.
ALSTOM T&D Protection & Control Ltd cannot be held responsible for any reliance on any decisions taken on its contents without specific advice.
Publication R4056R 039920 CPS Printed in England.
ALSTOM T&D Protec tion & Control Ltd